problema con postgres y rails

[Montes28]

la situacion es la siguiente : estoy migrando la aplicacion a un servidor con centos 6 y la base de datos esta en otro servidor , como hago la levantar el servidor de rails ? obtengo el siguiente error

rails s
You have requested:
pg >= 0

The bundle currently has pg locked at 0.15.1.
Try running `bundle update pg`
Run `bundle install` to install missing gems.


intento instalar gem install pg

y obtengo este error

# gem install pg
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.

/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby extconf.rb
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
--with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.

Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby
--with-pg
--without-pg
--with-pg-dir
--without-pg-dir
--with-pg-include
--without-pg-include=${pg-dir}/include
--with-pg-lib
--without-pg-lib=${pg-dir}/lib
--with-pg-config
--without-pg-config
--with-pg_config
--without-pg_config


Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1 for inspection.
Results logged to /usr/local/rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1/ext/gem_make.out